<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        .father {
            width: 500px;
            height: 500px;
            background-color: pink;
        }

        .damao {
            width: 150px;
            height: 150px;
            background-color: purple;
        }

        .ermao {
            width: 200px;
            height: 200px;
            background-color: skyblue;
        }
    </style>
</head>

<body>
    <!-- 快捷键 father>.damao+.ermao -->
    <div class="father">
        <div class="damao"></div>
        <div class="ermao"></div>
    </div>
</body>

</html>